User blog comment:Trevastyah/Mistakes done by beginners in competative./@comment-31722743-20170412025730

Novice Mistakes:

People think Ash Greninja is better than Protean Greninja.

People thing that Charizard X is better than Charizard Y only because it look like a shiny.

People think that pokemon with high power are better than anything else, regardless of type advantages.

People don't take into account opponent abilities. (Using Hydro Pump on a pokemon with Storm Drain)

People not equipping items.

The afformentioned Overheat. (and other moves of similar stature)

People expecting a 1v1 but getting a 6v1 instead.

Not everyone who doesn't have the most recent badge is a noob. Some people are smart.